linphone-iphone/linphone/exosip/jrequest.c

/*
  eXosip - This is the eXtended osip library.
  Copyright (C) 2002, 2003  Aymeric MOIZARD  - jack@atosc.org
  
  eXosip is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.
  
  eXosip is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
  
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#ifdef ENABLE_MPATROL
#include <mpatrol.h>
#endif

#include "eXosip2.h"

#ifndef WIN32
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#ifdef __APPLE_CC__
#include <unistd.h>
#endif
#else
#include <windows.h>
#include <Iphlpapi.h>
#endif

extern eXosip_t eXosip;

/* Private functions */
static int generating_request_out_of_dialog(osip_message_t **dest,
					    char *method_name, char *to,
					    char *transport, char *from,
					    char *proxy);
static int dialog_fill_route_set(osip_dialog_t *dialog,
				 osip_message_t *request);

/* should use cryptographically random identifier is RECOMMENDED.... */
/* by now this should lead to identical call-id when application are
   started at the same time...   */
char *
osip_call_id_new_random()
{
  char *tmp = (char *)osip_malloc(33);
  unsigned int number = osip_build_random_number();
  sprintf(tmp,"%u",number);
  return tmp;
}

char *
osip_from_tag_new_random(void)
{
  return osip_call_id_new_random();
}

char *
osip_to_tag_new_random(void)
{
  return osip_call_id_new_random();
}

unsigned int
via_branch_new_random(void)
{
  return osip_build_random_number();
}

/* prepare a minimal request (outside of a dialog) with required headers */
/* 
   method_name is the type of request. ("INVITE", "REGISTER"...)
   to is the remote target URI
   transport is either "TCP" or "UDP" (by now, only UDP is implemented!)
*/
static int
generating_request_out_of_dialog(osip_message_t **dest, char *method_name,
				 char *to, char *transport, char *from,
				 char *proxy)
{
  /* Section 8.1:
     A valid request contains at a minimum "To, From, Call-iD, Cseq,
     Max-Forwards and Via
  */
  int i;
  osip_message_t *request;
#ifdef SM
  char *locip=NULL;
#else
  char locip[50];
#endif
  int doing_register;
  char *register_callid_number = NULL;

  i = osip_message_init(&request);
  if (i!=0) return -1;

  /* prepare the request-line */
  osip_message_set_method(request, osip_strdup(method_name));
  osip_message_set_version(request, osip_strdup("SIP/2.0"));
  osip_message_set_status_code(request, 0);
  osip_message_set_reason_phrase(request, NULL);

  doing_register = 0==strcmp("REGISTER", method_name);

  if (doing_register)
    {
      osip_uri_init(&(request->req_uri));
      i = osip_uri_parse(request->req_uri, proxy);
      if (i!=0)
	{
	  goto brood_error_1;
	}
      osip_message_set_to(request, from);
    }
  else
    {
      /* in any cases except REGISTER: */
      i = osip_message_set_to(request, to);
      if (i!=0)
	{
     OSIP_TRACE (osip_trace
		 (__FILE__, __LINE__, OSIP_ERROR, NULL,
	     "ERROR: callee address does not seems to be a sipurl: %s\n", to));
	  goto brood_error_1;
	}
      if (proxy!=NULL && proxy[0] != 0)
	{  /* equal to a pre-existing route set */
	   /* if the pre-existing route set contains a "lr" (compliance
	      with bis-08) then the req_uri should contains the remote target
	      URI */
	  osip_uri_param_t *lr_param;
	  osip_route_t *o_proxy;
#ifndef __VXWORKS_OS__
	  osip_route_init(&o_proxy);
#else
	  osip_route_init2(&o_proxy);
#endif
	  i = osip_route_parse(o_proxy, proxy);
	  if (i!=0) {
	    osip_route_free(o_proxy);
	    goto brood_error_1;
	  }

	  osip_uri_uparam_get_byname(o_proxy->url, "lr", &lr_param);
	  if (lr_param!=NULL) /* to is the remote target URI in this case! */
	    {
	      osip_uri_clone(request->to->url, &(request->req_uri));
	      /* "[request] MUST includes a Route header field containing
	       the route set values in order." */
	      osip_list_add(request->routes, o_proxy, 0);
	    }
	  else
	    /* if the first URI of route set does not contain "lr", the req_uri
	       is set to the first uri of route set */
	    {
	      request->req_uri = o_proxy->url;
	      o_proxy->url = NULL;
	      osip_route_free(o_proxy);
	      /* add the route set */
	      /* "The UAC MUST add a route header field containing
		 the remainder of the route set values in order.
		 The UAC MUST then place the remote target URI into
		 the route header field as the last value
	       */
	      osip_message_set_route(request, to);
	    }
	}
      else /* No route set (outbound proxy) is used */
	{
	  /* The UAC must put the remote target URI (to field) in the req_uri */
	    i = osip_uri_clone(request->to->url, &(request->req_uri));
	    if (i!=0) goto brood_error_1;
	}
    }
  /*guess the local ip since req uri is known */
#ifdef SM
	{
  		eXosip_get_localip_for(request->req_uri->host,&locip);
	}
#else
  eXosip_guess_ip_for_via(eXosip.ip_family, locip, 49);
#endif
  /* set To and From */
  osip_message_set_from(request, from);
  /* add a tag */
  osip_from_set_tag(request->from, osip_from_tag_new_random());
  
  /* set the cseq and call_id header */
    {
      osip_call_id_t *callid;
      osip_cseq_t *cseq;
      char *num;
      char  *cidrand;

      /* call-id is always the same for REGISTRATIONS */
      i = osip_call_id_init(&callid);
      if (i!=0) goto brood_error_1;
      cidrand = osip_call_id_new_random();
      osip_call_id_set_number(callid, cidrand);
      if (doing_register)
	register_callid_number = cidrand;

      osip_call_id_set_host(callid, osip_strdup(locip));
      request->call_id = callid;

      i = osip_cseq_init(&cseq);
      if (i!=0) goto brood_error_1;
      num = osip_strdup(doing_register ? "1" : "20" );
      osip_cseq_set_number(cseq, num);
      osip_cseq_set_method(cseq, osip_strdup(method_name));
      request->cseq = cseq;
    }

  /* always add the Max-Forward header */
  osip_message_set_max_forwards(request, "70"); /* a UA should start a request with 70 */

#define MASQUERADE_VIA
#ifdef MASQUERADE_VIA
  /* should be useless with compliant UA */
  if (eXosip.j_firewall_ip[0]!='\0')
  {
	  char *c_address = request->req_uri->host;

	  struct addrinfo *addrinfo;
	  struct __eXosip_sockaddr addr;
	  i = eXosip_get_addrinfo(&addrinfo, request->req_uri->host, 5060);
	  if (i==0)
		{
		  memcpy (&addr, addrinfo->ai_addr, addrinfo->ai_addrlen);
		  freeaddrinfo (addrinfo);
		  c_address = inet_ntoa (((struct sockaddr_in *) &addr)->sin_addr);
		  OSIP_TRACE (osip_trace
			  (__FILE__, __LINE__, OSIP_INFO1, NULL,
			  "eXosip: here is the resolved destination host=%s\n", c_address));
		}

	  if (eXosip_is_public_address(c_address))
	    {
	      char tmp[200];
	      snprintf(tmp, 200, "SIP/2.0/%s %s:%s;rport;branch=z9hG4bK%u", transport,
		      eXosip.j_firewall_ip,
		      eXosip.localport,
		      via_branch_new_random() );
	      osip_message_set_via(request, tmp);
	  }
	  else
	  {
	    char tmp[200];
	    if (eXosip.ip_family==AF_INET6)
	      snprintf(tmp, 200, "SIP/2.0/%s [%s]:%s;branch=z9hG4bK%u", transport,
		      locip,
		      eXosip.localport,
		      via_branch_new_random() );
	    else
	      snprintf(tmp, 200, "SIP/2.0/%s %s:%s;rport;branch=z9hG4bK%u", transport,
		      locip,
		      eXosip.localport,
		      via_branch_new_random() );
	    osip_message_set_via(request, tmp);
	  }
  }
  else
  {
    char tmp[200];
    if (eXosip.ip_family==AF_INET6)
      snprintf(tmp, 200, "SIP/2.0/%s [%s]:%s;branch=z9hG4bK%u", transport,
	      locip,
	      eXosip.localport,
	      via_branch_new_random() );
    else
      snprintf(tmp, 200, "SIP/2.0/%s %s:%s;rport;branch=z9hG4bK%u", transport,
	      locip,
	      eXosip.localport,
	      via_branch_new_random() );
    osip_message_set_via(request, tmp);
  }

#else
  {
    char tmp[200];
    if (eXosip.ip_family==AF_INET6)
      spnrintf(tmp, 200, "SIP/2.0/%s [%s]:%s;branch=z9hG4bK%u", transport,
	      locip,
	      eXosip.localport,
	      via_branch_new_random() );
    else
      spnrintf(tmp, 200, "SIP/2.0/%s %s:%s;rport;branch=z9hG4bK%u", transport,
	      locip,
	      eXosip.localport,
	      via_branch_new_random() );

    osip_message_set_via(request, tmp);
  }
#endif

  /* add specific headers for each kind of request... */

  if (0==strcmp("INVITE", method_name) || 0==strcmp("SUBSCRIBE", method_name))
    {
      char *contact;
      osip_from_t *a_from;
      int i;
      i = osip_from_init(&a_from);
      if (i==0)
	i = osip_from_parse(a_from, from);

      if (i==0 && a_from!=NULL
	  && a_from->url!=NULL && a_from->url->username!=NULL )
	{
	  contact = (char *) osip_malloc(50+strlen(a_from->url->username));

	  if (eXosip.j_firewall_ip[0]!='\0')
	    {
	      char *c_address = request->req_uri->host;

		  struct addrinfo *addrinfo;
		  struct __eXosip_sockaddr addr;
		  i = eXosip_get_addrinfo(&addrinfo, request->req_uri->host, 5060);
		  if (i==0)
			{
			  memcpy (&addr, addrinfo->ai_addr, addrinfo->ai_addrlen);
			  freeaddrinfo (addrinfo);
			  c_address = inet_ntoa (((struct sockaddr_in *) &addr)->sin_addr);
			  OSIP_TRACE (osip_trace
				  (__FILE__, __LINE__, OSIP_INFO1, NULL,
				  "eXosip: here is the resolved destination host=%s\n", c_address));
			}

	      if (eXosip_is_public_address(c_address))
		{
		  if (eXosip.localport==NULL)
		    sprintf(contact, "<sip:%s@%s>", a_from->url->username,
			    eXosip.j_firewall_ip);
		  else
		    sprintf(contact, "<sip:%s@%s:%s>", a_from->url->username,
			    eXosip.j_firewall_ip,
			    eXosip.localport);
		}
	      else
		{
		  if (eXosip.localport==NULL)
		    sprintf(contact, "<sip:%s@%s>", a_from->url->username,
			    locip);
		  else
		    sprintf(contact, "<sip:%s@%s:%s>", a_from->url->username,
			    locip,
			    eXosip.localport);
		}
	    }
	  else
	    {
	      if (eXosip.localport==NULL)
		sprintf(contact, "<sip:%s@%s>", a_from->url->username,
			locip);
	      else
		sprintf(contact, "<sip:%s@%s:%s>", a_from->url->username,
			locip,
			eXosip.localport);
	    }
	  osip_message_set_contact(request, contact);
	  osip_free(contact);
	}
      osip_from_free(a_from);

      /* This is probably useless for other messages */
      osip_message_set_allow(request, "INVITE");
      osip_message_set_allow(request, "ACK");
      osip_message_set_allow(request, "CANCEL");
      osip_message_set_allow(request, "BYE");
      osip_message_set_allow(request, "OPTIONS");
      osip_message_set_allow(request, "REFER");
      osip_message_set_allow(request, "SUBSCRIBE");
      osip_message_set_allow(request, "NOTIFY");
      osip_message_set_allow(request, "MESSAGE");
    }

  if (0==strcmp("SUBSCRIBE", method_name))
    {
      osip_message_set_header(request, "Event", "presence");
#ifdef SUPPORT_MSN
      osip_message_set_accept(request, "application/xpidf+xml");
#else
      osip_message_set_accept(request, "application/pidf+xml");
#endif
    }
  else if (0==strcmp("REGISTER", method_name))
    {
    }
  else if (0==strcmp("INFO", method_name))
    {
    }
  else if (0==strcmp("OPTIONS", method_name))
    {
      osip_message_set_accept(request, "application/sdp");
    }

  osip_message_set_user_agent(request, eXosip.user_agent);
  /*  else if ... */
  *dest = request;
#ifdef SM
  osip_free(locip);
#endif
  return 0;

 brood_error_1:
  osip_message_free(request);
  *dest = NULL;
#ifdef SM
  if (locip!=NULL) osip_free(locip);
#endif
  return -1;
}

int
generating_register(osip_message_t **reg, char *from,
		    char *proxy, char *contact, int expires)
{
  osip_from_t *a_from;
  osip_via_t *via;
  int i;
  char * locip;

  i = generating_request_out_of_dialog(reg, "REGISTER", NULL, "UDP",
				       from, proxy);
  if (i!=0) return -1;

  /*get the local ip from the via already established by generating_request_out_of_dialog */
  if (osip_message_get_via((*reg),0,&via)==0){
    locip=via->host;
  }else return -1;

  if (contact==NULL)
    {
      i = osip_from_init(&a_from);
      if (i==0)
	i = osip_from_parse(a_from, from);

      if (i==0 && a_from!=NULL
	  && a_from->url!=NULL && a_from->url->username!=NULL )
	{
	  contact = (char *) osip_malloc(50+strlen(a_from->url->username));
	  
		if (eXosip.ip_family==AF_INET6)
			sprintf(contact, "<sip:%s@[%s]:%s>", a_from->url->username,
			locip,
			eXosip.localport!=NULL ? eXosip.localport : "5060");
		else
			sprintf(contact, "<sip:%s@%s:%s>", a_from->url->username,
			locip,
			eXosip.localport!=NULL ? eXosip.localport : "5060");
	  osip_message_set_contact(*reg, contact);
	  osip_free(contact);
	}
      osip_from_free(a_from);
    }
  else
    {
      osip_message_set_contact(*reg, contact);
    }

  {
    char exp[10]; /* MUST never be ouside 1 and 3600 */
    snprintf(exp, 9, "%i", expires);
    osip_message_set_expires(*reg, exp);
  }

  osip_message_set_content_length(*reg, "0");
  
  return 0;
}

/* this method can't be called unless the previous
   INVITE transaction is over. */
int eXosip_build_initial_invite(osip_message_t **invite, char *to, char *from,
				char *route, char *subject)
{
  int i;

  if (to!=NULL && *to=='\0')
    return -1;

  osip_clrspace(to);
  osip_clrspace(subject);
  osip_clrspace(from);
  osip_clrspace(route);
  if (route!=NULL && *route=='\0')
    route=NULL;
  if (subject!=NULL && *subject=='\0')
    subject=NULL;

  i = generating_request_out_of_dialog(invite, "INVITE", to, "UDP", from,
				       route);
  if (i!=0) return -1;
  
#if 0
  if (subject==NULL)
	  osip_message_set_subject(*invite, "New Call");
  else
	  osip_message_set_subject(*invite, subject);
#else
  if (subject!=NULL)
	  osip_message_set_subject(*invite, subject);
#endif

  /* after this delay, we should send a CANCEL */
  osip_message_set_expires(*invite, "120");

  /* osip_message_set_organization(*invite, "Jack's Org"); */
  return 0;
}

/* this method can't be called unless the previous
   INVITE transaction is over. */
int eXosip_build_initial_options(osip_message_t **options, char *to, char *from,
				 char *route)
{
  int i;

  if (to!=NULL && *to=='\0')
    return -1;

  osip_clrspace(to);
  osip_clrspace(from);
  osip_clrspace(route);
  if (route!=NULL && *route=='\0')
    route=NULL;

  i = generating_request_out_of_dialog(options, "OPTIONS", to, "UDP", from,
				       route);
  if (i!=0) return -1;

  /* after this delay, we should send a CANCEL */
  osip_message_set_expires(*options, "120");

  /* osip_message_set_organization(*invite, "Jack's Org"); */
  return 0;
}

/* this method can't be called unless the previous
   INVITE transaction is over. */
int generating_initial_subscribe(osip_message_t **subscribe, char *to,
				 char *from, char *route)
{
  int i;

  if (to!=NULL && *to=='\0')
    return -1;

  osip_clrspace(to);
  osip_clrspace(from);
  osip_clrspace(route);
  if (route!=NULL && *route=='\0')
    route=NULL;

  i = generating_request_out_of_dialog(subscribe, "SUBSCRIBE", to, "UDP", from,
				       route);
  if (i!=0) return -1;
  
#ifdef LOW_EXPIRE
  osip_message_set_expires(*subscribe, "120");
#else
  osip_message_set_expires(*subscribe, "3600");
#endif

  /* osip_message_set_organization(*subscribe, "Jack's Org"); */
  return 0;
}

/* this method can't be called unless the previous
   INVITE transaction is over. */
int generating_message(osip_message_t **message, char *to, char *from,
		       char *route, char *buff)
{
  int i;

  if (to!=NULL && *to=='\0')
    return -1;

  osip_clrspace(to);
  /*  osip_clrspace(buff); */
  osip_clrspace(from);
  osip_clrspace(route);
  if (route!=NULL && *route=='\0')
    route=NULL;
  if (buff!=NULL && *buff=='\0')
    return -1; /* at least, the message must be of length >= 1 */
  
  i = generating_request_out_of_dialog(message, "MESSAGE", to, "UDP", from,
				       route);
  if (i!=0) return -1;
  
  osip_message_set_expires(*message, "120");
  osip_message_set_body(*message, buff, strlen(buff));
  osip_message_set_content_type(*message, "text/plain");

  /* osip_message_set_organization(*message, "Jack's Org"); */


  return 0;
}

/* this method can't be called unless the previous
   INVITE transaction is over. */
int
generating_publish(osip_message_t **message, char *to, char *from,
		   char *route)
{
  int i;

  if (to!=NULL && *to=='\0')
    return -1;

  osip_clrspace(to);
  osip_clrspace(from);
  osip_clrspace(route);
  if (route!=NULL && *route=='\0')
    route=NULL;
  
  i = generating_request_out_of_dialog(message, "PUBLISH", to, "UDP", from,
				       route);
  if (i!=0) return -1;
  
  /* osip_message_set_organization(*message, "Jack's Org"); */

  return 0;
}


int
generating_options(osip_message_t **options, char *from, char *to, char *proxy)
{
  int i;
  i = generating_request_out_of_dialog(options, "OPTIONS", to, "UDP",
				       from, proxy);
  if (i!=0) return -1;

#if 0
  if (sdp!=NULL)
    {
      osip_message_set_content_type(*options, "application/sdp");
      osip_message_set_body(*options, sdp);
    }
#endif

  return 0;
}

int
generating_info(osip_message_t **info, char *from, char *to, char *proxy)
{
  int i;
  i = generating_request_out_of_dialog(info, "INFO", to, "UDP",
				       from, proxy);
  if (i!=0) return -1;
  return 0;
}


static int
dialog_fill_route_set(osip_dialog_t *dialog, osip_message_t *request)
{
  /* if the pre-existing route set contains a "lr" (compliance
     with bis-08) then the req_uri should contains the remote target
     URI */
  int i;
  int pos=0;
  osip_uri_param_t *lr_param;
  osip_route_t *route;
  char *last_route;
  /* AMD bug: fixed 17/06/2002 */

  if (dialog->type==CALLER)
    {
      pos = osip_list_size(dialog->route_set)-1;
      route = (osip_route_t*)osip_list_get(dialog->route_set, pos);
    }
  else
    route = (osip_route_t*)osip_list_get(dialog->route_set, 0);
    
  osip_uri_uparam_get_byname(route->url, "lr", &lr_param);
  if (lr_param!=NULL) /* the remote target URI is the req_uri! */
    {
      i = osip_uri_clone(dialog->remote_contact_uri->url,
		    &(request->req_uri));
      if (i!=0) return -1;
      /* "[request] MUST includes a Route header field containing
	 the route set values in order." */
      /* AMD bug: fixed 17/06/2002 */
      pos=0; /* first element is at index 0 */
      while (!osip_list_eol(dialog->route_set, pos))
	{
	  osip_route_t *route2;
	  route = osip_list_get(dialog->route_set, pos);
	  i = osip_route_clone(route, &route2);
	  if (i!=0) return -1;
	  if (dialog->type==CALLER)
	    osip_list_add(request->routes, route2, 0);
	  else
	    osip_list_add(request->routes, route2, -1);
	  pos++;
	}
      return 0;
    }

  /* if the first URI of route set does not contain "lr", the req_uri
     is set to the first uri of route set */
  
  
  i = osip_uri_clone(route->url, &(request->req_uri));
  if (i!=0) return -1;
  /* add the route set */
  /* "The UAC MUST add a route header field containing
     the remainder of the route set values in order. */
  pos=0; /* yes it is */
  
  while (!osip_list_eol(dialog->route_set, pos)) /* not the first one in the list */
    {
      osip_route_t *route2;
      route = osip_list_get(dialog->route_set, pos);
      i = osip_route_clone(route, &route2);
      if (i!=0) return -1;
      if (dialog->type==CALLER)
	{
	  if (pos!=osip_list_size(dialog->route_set)-1)
	    osip_list_add(request->routes, route2, 0);
	  else
	    osip_route_free(route2);
	}
      else
	{
	  if (!osip_list_eol(dialog->route_set, pos+1))
	    osip_list_add(request->routes, route2, -1);
	  else
	    osip_route_free(route2);
	}
      pos++;
    }

  /* The UAC MUST then place the remote target URI into
     the route header field as the last value */
  i = osip_uri_to_str(dialog->remote_contact_uri->url, &last_route);
  if (i!=0) return -1;
  i = osip_message_set_route(request, last_route);
  osip_free(last_route);
  if (i!=0) { return -1; }
  
  /* route header and req_uri set */
  return 0;
}

int
_eXosip_build_request_within_dialog(osip_message_t **dest, char *method_name,
				   osip_dialog_t *dialog, char *transport)
{
  int i;
  osip_message_t *request;
#ifdef SM
  char *locip=NULL;
#else
  char locip[50];
#endif
  
  i = osip_message_init(&request);
  if (i!=0) return -1;

  if (dialog->remote_contact_uri==NULL)
    {
      /* this dialog is probably not established! or the remote UA
	 is not compliant with the latest RFC
      */
      osip_message_free(request);
      return -1;
    }
#ifdef SM
  eXosip_get_localip_for(dialog->remote_contact_uri->url->host,&locip);
#else
  eXosip_guess_ip_for_via(eXosip.ip_family, locip, 49);
#endif
  /* prepare the request-line */
  request->sip_method  = osip_strdup(method_name);
  request->sip_version = osip_strdup("SIP/2.0");
  request->status_code   = 0;
  request->reason_phrase = NULL;

  /* and the request uri???? */
  if (osip_list_eol(dialog->route_set, 0))
    {
      /* The UAC must put the remote target URI (to field) in the req_uri */
      i = osip_uri_clone(dialog->remote_contact_uri->url, &(request->req_uri));
      if (i!=0) goto grwd_error_1;
    }
  else
    {
      /* fill the request-uri, and the route headers. */
      dialog_fill_route_set(dialog, request);
    }
  
  /* To and From already contains the proper tag! */
  i = osip_to_clone(dialog->remote_uri, &(request->to));
  if (i!=0) goto grwd_error_1;
  i = osip_from_clone(dialog->local_uri, &(request->from));
  if (i!=0) goto grwd_error_1;

  /* set the cseq and call_id header */
  osip_message_set_call_id(request, dialog->call_id);

  if (0==strcmp("ACK", method_name))
    {
      osip_cseq_t *cseq;
      char *tmp;
      i = osip_cseq_init(&cseq);
      if (i!=0) goto grwd_error_1;
      tmp = osip_malloc(20);
      sprintf(tmp,"%i", dialog->local_cseq);
      osip_cseq_set_number(cseq, tmp);
      osip_cseq_set_method(cseq, osip_strdup(method_name));
      request->cseq = cseq;
    }
  else
    {
      osip_cseq_t *cseq;
      char *tmp;
      i = osip_cseq_init(&cseq);
      if (i!=0) goto grwd_error_1;
      dialog->local_cseq++; /* we should we do that?? */
      tmp = osip_malloc(20);
      sprintf(tmp,"%i", dialog->local_cseq);
      osip_cseq_set_number(cseq, tmp);
      osip_cseq_set_method(cseq, osip_strdup(method_name));
      request->cseq = cseq;
    }
  
  /* always add the Max-Forward header */
  osip_message_set_max_forwards(request, "70"); /* a UA should start a request with 70 */


  /* even for ACK for 2xx (ACK within a dialog), the branch ID MUST
     be a new ONE! */
#ifdef MASQUERADE_VIA
  /* should be useless with compliant UA */
  if (eXosip.j_firewall_ip[0]!='\0')
  {
	  char *c_address = request->req_uri->host;

	  struct addrinfo *addrinfo;
	  struct __eXosip_sockaddr addr;
	  i = eXosip_get_addrinfo(&addrinfo, request->req_uri->host, 5060);
	  if (i==0)
		{
		  memcpy (&addr, addrinfo->ai_addr, addrinfo->ai_addrlen);
		  freeaddrinfo (addrinfo);
		  c_address = inet_ntoa (((struct sockaddr_in *) &addr)->sin_addr);
		  OSIP_TRACE (osip_trace
			  (__FILE__, __LINE__, OSIP_INFO1, NULL,
			  "eXosip: here is the resolved destination host=%s\n", c_address));
		}

	  if (eXosip_is_public_address(c_address))
	  {
		    char tmp[200];
		    sprintf(tmp, "SIP/2.0/%s %s:%s;rport;branch=z9hG4bK%u", transport,
			    eXosip.j_firewall_ip,
			    eXosip.localport,
			    via_branch_new_random() );
		    osip_message_set_via(request, tmp);
	  }
	  else
	  {
	    char tmp[200];
	    if (eXosip.ip_family==AF_INET6)
	      snprintf(tmp, 200, "SIP/2.0/%s [%s]:%s;branch=z9hG4bK%u", transport,
		      locip,
		      eXosip.localport,
		      via_branch_new_random() );
	    else
	      snprintf(tmp, 200, "SIP/2.0/%s %s:%s;rport;branch=z9hG4bK%u", transport,
		      locip,
		      eXosip.localport,
		      via_branch_new_random() );
	      
	    osip_message_set_via(request, tmp);
	  }
  }
  else
  {
    char tmp[200];
    if (eXosip.ip_family==AF_INET6)
      snprintf(tmp, 200, "SIP/2.0/%s [%s]:%s;branch=z9hG4bK%u", transport,
	      locip,
	      eXosip.localport,
	      via_branch_new_random() );
    else
      snprintf(tmp, 200, "SIP/2.0/%s %s:%s;rport;branch=z9hG4bK%u", transport,
	      locip,
	      eXosip.localport,
	      via_branch_new_random() );

    osip_message_set_via(request, tmp);
  }

#else
  {
    char tmp[200];
    if (eXosip.ip_family==AF_INET6)
      sprintf(tmp, "SIP/2.0/%s [%s]:%s;branch=z9hG4bK%u", transport,
	      locip, eXosip.localport,
	      via_branch_new_random());
    else
      sprintf(tmp, "SIP/2.0/%s %s:%s;rport;branch=z9hG4bK%u", transport,
	      locip, eXosip.localport,
	      via_branch_new_random());

    osip_message_set_via(request, tmp);
  }
#endif

  /* add specific headers for each kind of request... */

#if 0
  if (0==strcmp("INVITE", method_name) || 0==strcmp("SUBSCRIBE", method_name))
#endif
    {
      char contact[200];
      if (eXosip.j_firewall_ip[0]!='\0')
	{
	  char *c_address = request->req_uri->host;

	  struct addrinfo *addrinfo;
	  struct __eXosip_sockaddr addr;
	  i = eXosip_get_addrinfo(&addrinfo, request->req_uri->host, 5060);
	  if (i==0)
		{
		  memcpy (&addr, addrinfo->ai_addr, addrinfo->ai_addrlen);
		  freeaddrinfo (addrinfo);
		  c_address = inet_ntoa (((struct sockaddr_in *) &addr)->sin_addr);
		  OSIP_TRACE (osip_trace
			  (__FILE__, __LINE__, OSIP_INFO1, NULL,
			  "eXosip: here is the resolved destination host=%s\n", c_address));
		}

	  if (eXosip_is_public_address(c_address))
	    {
	      sprintf(contact, "<sip:%s@%s:%s>", dialog->local_uri->url->username,
		      eXosip.j_firewall_ip,
		      eXosip.localport);
	    }
	  else
	    {
	      sprintf(contact, "<sip:%s@%s:%s>", dialog->local_uri->url->username,
		      locip,
		      eXosip.localport);
	    }
	}
      else
	{
	      sprintf(contact, "<sip:%s@%s:%s>", dialog->local_uri->url->username,
		      locip,
		      eXosip.localport);
	}
      osip_message_set_contact(request, contact);
      /* Here we'll add the supported header if it's needed! */
      /* the require header must be added by the upper layer if needed */
    }

  if (0==strcmp("SUBSCRIBE", method_name))
    {
      osip_message_set_header(request, "Event", "presence");
#ifdef SUPPORT_MSN
      osip_message_set_accept(request, "application/xpidf+xml");
#else
      osip_message_set_accept(request, "application/pidf+xml");
#endif
    }
  else if (0==strcmp("NOTIFY", method_name))
    {
    }
  else if (0==strcmp("INFO", method_name))
    {

    }
  else if (0==strcmp("OPTIONS", method_name))
    {
      osip_message_set_accept(request, "application/sdp");
    }
  else if (0==strcmp("ACK", method_name))
    {
      /* The ACK MUST contains the same credential than the INVITE!! */
      /* TODO... */
    }

  osip_message_set_user_agent(request, eXosip.user_agent);
  /*  else if ... */
  *dest = request;
  return 0;

  /* grwd_error_2: */
  dialog->local_cseq--;
 grwd_error_1:
  osip_message_free(request);
  *dest = NULL;
  return -1;
}

/* this request is only build within a dialog!! */
int
generating_bye(osip_message_t **bye, osip_dialog_t *dialog)
{
  int i;
  i = _eXosip_build_request_within_dialog(bye, "BYE", dialog, "UDP");
  if (i!=0) return -1;

  return 0;
}

/* this request is only build within a dialog! (but should not!) */
int
generating_refer_outside_dialog(osip_message_t **refer, char *refer_to, char *from, char *to, char *proxy)
{
  int i;
  i = generating_request_out_of_dialog(refer, "REFER", to, "UDP",
				       from, proxy);
  if (i!=0) return -1;

  osip_message_set_header(*refer, "Refer-to", refer_to);
  return 0;
}

/* this request is only build within a dialog! (but should not!) */
int
generating_refer(osip_message_t **refer, osip_dialog_t *dialog, char *refer_to)
{
  int i;
  i = _eXosip_build_request_within_dialog(refer, "REFER", dialog, "UDP");
  if (i!=0) return -1;

  osip_message_set_header(*refer, "Refer-to", refer_to);

  return 0;
}

/* this request can be inside or outside a dialog */
int
generating_options_within_dialog(osip_message_t **options, osip_dialog_t *dialog)
{
  int i;
  i = _eXosip_build_request_within_dialog(options, "OPTIONS", dialog, "UDP");
  if (i!=0) return -1;

#if 0
  if (sdp!=NULL)
    {
      osip_message_set_content_type(*options, "application/sdp");
      osip_message_set_body(*options, sdp);
    }
#endif

  return 0;
}

int
generating_info_within_dialog(osip_message_t **info, osip_dialog_t *dialog)
{
  int i;
  i = _eXosip_build_request_within_dialog(info, "INFO", dialog, "UDP");
  if (i!=0) return -1;
  return 0;
}

/* It is RECOMMENDED to only cancel INVITE request */
int
generating_cancel(osip_message_t **dest, osip_message_t *request_cancelled)
{
  int i;
  osip_message_t *request;
  
  i = osip_message_init(&request);
  if (i!=0) return -1;
  
  /* prepare the request-line */
  osip_message_set_method(request, osip_strdup("CANCEL"));
  osip_message_set_version(request, osip_strdup("SIP/2.0"));
  osip_message_set_status_code(request, 0);
  osip_message_set_reason_phrase(request, NULL);

  i = osip_uri_clone(request_cancelled->req_uri, &(request->req_uri));
  if (i!=0) goto gc_error_1;
  
  i = osip_to_clone(request_cancelled->to, &(request->to));
  if (i!=0) goto gc_error_1;
  i = osip_from_clone(request_cancelled->from, &(request->from));
  if (i!=0) goto gc_error_1;
  
  /* set the cseq and call_id header */
  i = osip_call_id_clone(request_cancelled->call_id, &(request->call_id));
  if (i!=0) goto gc_error_1;
  i = osip_cseq_clone(request_cancelled->cseq, &(request->cseq));
  if (i!=0) goto gc_error_1;
  osip_free(request->cseq->method);
  request->cseq->method = osip_strdup("CANCEL");
  
  /* copy ONLY the top most Via Field (this method is also used by proxy) */
  {
    osip_via_t *via;
    osip_via_t *via2;
    i = osip_message_get_via(request_cancelled, 0, &via);
    if (i!=0) goto gc_error_1;
    i = osip_via_clone(via, &via2);
    if (i!=0) goto gc_error_1;
    osip_list_add(request->vias, via2, -1);
  }

  /* add the same route-set than in the previous request */
  {
    int pos=0;
    osip_route_t *route;
    osip_route_t *route2;
    while (!osip_list_eol(request_cancelled->routes, pos))
      {
	route = (osip_route_t*) osip_list_get(request_cancelled->routes, pos);
	i = osip_route_clone(route, &route2);
	if (i!=0) goto gc_error_1;
	osip_list_add(request->routes, route2, -1);
	pos++;
      }
  }

  osip_message_set_max_forwards(request, "70"); /* a UA should start a request with 70 */
  osip_message_set_user_agent(request, eXosip.user_agent);

  *dest = request;
  return 0;

 gc_error_1:
  osip_message_free(request);
  *dest = NULL;
  return -1;
}


int
generating_ack_for_2xx(osip_message_t **ack, osip_dialog_t *dialog)
{
  int i;
  i = _eXosip_build_request_within_dialog(ack, "ACK", dialog, "UDP");
  if (i!=0) return -1;

  return 0;
}